Process for the manufacture of spelter from ferruginous and admixed zinc-blend ores.



A 1.1. {IML/UID;L PROCESS FOR'THEIVIANUFACTURE 0F vSIELTER 4FROM FERRUGINOUS AND ADNIIXED ZINC BLEND GRES.

APPLICATION FILED SEPT.I0, `I9I3.

1,157,375. Patented 001:. '19, 1915.

COLCO. SO2 l CO/TE,

77E, Q0a I /Vg/V s/L VER /Nr :MED/RTE.

Fis/Dues 6h VfR Fenu/15s,

JOHN JAMES FINGLAND, OF KASLO, BRITISH COLUMBIA,.CANADA.

'PROCESS ron THE MANUFAoTUn-E'or SPELTER FROM rERRUGINoUs AND ADMIXED ZINC-BLEND onEs.

Specification of Letters Yatent. l

Patented Oct. i9, 1915.

Application filed September 10, 1913. Serial No. 789,09.

To all whom t may concer/1,.'

Be it known that I, JOHN JAMES FING- LANn, of the city of Kaslo, in the Test Kootenay district of the Province of British Columbia, Canada, have invented new and useful Improvements in Processes for the Manufacture of Spelter from Ferruginous and Admixed Zinc-Blend Orcs, of which the following is a specification.

i In the ordinary treatment of admixed suliid ores by gravity concentration two products are obtained; one containing the major portion of the lead contents, the other containing the major portion of the zinc contents, together With various minerals or admixed minerals of like specific gravity, such as, pyrite, pyrrhotite, copper pyrites, galena, barytes, etc. This zinc product ordinarily contains insufficient zinc contents, and excessive proportions of deleterious substances, such as iron, to render it expedient to recover the zinc by distillation in the ordinary manner. It is frequently subjected to an enriching process, such as, roasting and magnetic separation in order to produce a product of marketable grade of zinc contents.

This invention relates to the treatment of this admiXed Zinc concentrate from gravity separation, or enriched products derived therefrom, not amenable to treatment by the ordinary process, through the presence of deleterious substances, such as lime; orA

crude ores of a like character but containing galena in greater proportion which, owing to their physical character and high Zinc contents are not amenable to gravity concentration, nor to direct smelting on a lead basis; but only such ores as arefcomparatively free, or which can be freed from silicious matter by a preliminary treatment.

It has for its object the treatment of these types of ores and products by a smelting process, for the recovery of spelter, Vand at the same time collecting the lead, copper, silver, and gold, which may be contained in them, in the form of products amenable to their ordinary metallurgical treatment; thus rendering the recovery of the metal contents of these ores and products more complete and expeditious than is possible by the ordinary process.

This invention commises three distinct stepsz-L The preparation of a zinc calcic oXid sulfid mette. 2. The reduction of this matte by carbonaceous matter, for the' production of spelter and zinc dust. 3. The productionvoi:l spelter from the Zinc dust of the previous operation.

The zinc calcio oXid sullid matte possesses .the following metallurgical composition,

Zn (Fe) 4Ca (Ba) ,S304

4Zn(Fe) 0,3Ca (Ba) S l The mixtures thus prepared are heated gradually in a gas-fired, basic-lined reverberatory furnace, in such a manner that the charge is built up with the more plumbiferous ores containing excess of lime in the early stages, finishing with the more zinkiferous ores with a corresponding deficiency of lime. During the heating the galeria contained in the charge reacts With lime, forming calcio sulfid and ,litharge (PbO), the latter volatilizing, to be collected as flue dust or lead fume. When the lead has been thus removed, the temperature is gradually raised to about 15000 C. when ythe mass, after fritting together at lower temperatures, assumes the liquid1 state as zinc calcio oxid sulfid matte; a stablesubstance at that temperature in absence of silicious, or carbonaceous matter, and which is capable of assimilating and dissolving small quantities of sulfids or oXids otzinc, iron, or lime which may be in excess of the aforementioned proportions. VThis matte is also ren- .dered more fluid, c. e., the melting point is a tendency to oxidize the zinc`in lthe condenser. Distillation of the zinc' is then effected in a basic-lined retort at temperatures between 11000 C and 1200C C, for the recovery ot' spelter and zinc dust. The residues from the retort are screened free from coke, the iron removed by magnetic means,

before being returned to the initial stage,

either crude, or roasted, to collect a further quota of gold, silver, and copper contained in the ores, until they are sufficiently enriched in these metals to form a valuable byproduct. n

The zinc dust collected from the previous operation is mixed with a sufficiency of the cleaned calcic sulfid residue to allow of the formation ofthe zinc calcic oxid sulfid matte by union with the Zinc oxid contained inthe Zinc dust. This admixture is heated .in a

basic-lined retort, litted with feed inlet and taphole` so as to allow of continuous operation. The distillation and condensation of the spelter is thus conducted without the presenceof oxidizing gases, which lordinarily occur when carbonaceous matter is utilized to decompose the zinc oxid. The tapped matte is returned to `the previous step.

The accompanying drawing represents a diagrammatic representation of the process in seven stages.

In stage 1 the ores and fiuxes, together' with the return products are mixed according to the already indicated equations. (lrude ores are represented by the formula Zn(Fe)S; roasted ores, by'Zn(Fe)O; the return product from stage G by, Ca(Ba)S; the return product from stage 7 by, mCaG, f/CaCwand .eCaSO4- In stage Qtheproductionfof the indicated, also the removal sulfur dioxid 02), carbon dioxid (CO2), and lead fume,`

well as, the addition of sulfate of lime to the charge to' correct high melting point irregularities. C

1n stage 3 the preliminary reduction takes place with'removalof CO2, CO, .and SO2 gases. y

In stage l distillation is eifected, with re-l covery of spelt-er and zinc dust., In lthe case of silverlessl ores, -the residues from this stage are rejected. Where the ores are suiiiciently argentiferous to give a valuable by- `matte is inrets product at this-stage, they are also removed from the process here; but where the silver y valuesl are intermediate between these eX-` I tremes they are treated in stage 6.

' In stage 6 the coke is screened out and the residue magnetically treated for the recovery of an iron by-product. The remaining calcic sulfid (Caid) residue Ahas a threefold purpose: It is used to mix with roasted ores in the initial stage; it is utilized to mix with the zinc dust vof the 4th stage, resulting in the production of spelter and matte in the 5th stage; (the vlatter roduct being identical with the product from the 2nd stage it is returned to stageV 3); lastly, it passes to stage 7 te be roasted, an admiXture of lime, carbonate of lime', and sulfate of lime resulting, which is returned to the inl itial stage to admix with crude ores.-

What I claim and desire to secure by Letters Patent, is

-1. The herein described. steps in the process of manufacturing spelter from ferruginous and admixed lead and Zinc blende ores,

which consists in heating a mixture of crude ore, roasted ore, and lime, thereby forming litharge and maintaining the h'eat treatment until the litharge has been driven 0H by volatilization.

2. lThe herein described steps in the process of manufacturing spelt-er from ferrugi- 'nous and admixed lead and zinc blende ores,

which consists in heating a mixture of crude ore, roasted ore, and lime, thereby 4formlng litharge and maintaining the heat treatment4 until the litharge has been driven o by volatilization, and subsequently continuingthe heat treatment at a raised temperature until a liquid Zinc calcic oxid suld matte is produced.

3. The herein described steps inthe process of manufacturing spelter from erruginous and admixed lead and zinc blende ores. which consists in heating a mixture vof crude ore, roasted ore, andlime, thereby forming litharge, maintaining the heat treatment until the litharge has been driven off by volatilization, and subsequently continuing the heat treatment at a temperature of substantially 1500O C. until a liquid. zinc -calcic oxid sulfid matte is produced.

1. The herein` described steps inthe process of manufacturing spelter from ferruginous and admixed ores, which consists in 'A producing a zinc calcic oxid suli'id matte by heat treatment, coolingand crushing the matte, heating the crushed matte, together with carbonaceous matter out of Contact with the air, and subsequently distilling the zinc.

5. The herein described steps in the process of manufacturing spelter frorn'ferruginous and admixed ores, which consists in producing a zinc calcic oxidsuliid matte by heat ,treatment` V,cooling and crushing themaite, heating the crushed matte together with carbonaceous matterl out of Contact witlithe air, subsequently distilling the zinc, screening the residue, moving the iron by magnetic treatment, and roasting the prod uct.

6. The herein-described process 'of manu-V a, liquid zinc calcio oxid suld matte is produced, cooling and crushing the matte, mixing the crushed matte with one half its 'any sulfate of lime to calcio sulfid, and the removal of gases having a tendency to oX idize the zinc, and subsequently distilling the Zinc.

` JOHN JAMES FINGLAND. Vitnesses:

H. S. vVrIELLAi/Is, JAMES ANDERSON. 

